Probably a lot of different ways you can handle this with JavaScript. You can use the addField object and add your invoice number to the newly created field with JS. Problem is the counter you'll need to increment the number. You can handle this with a hidden field on the form.
ted
The author of numerous books on Acrobat, Photoshop, Illustrator and the Adobe Creative Suite, and an international speaker on Adobe Acrobat, Ted Padova is a well-known PDF guru.
ted
The author of numerous books on Acrobat, Photoshop, Illustrator and the Adobe Creative Suite, and an international speaker on Adobe Acrobat, Ted Padova is a well-known PDF guru.